Work supports for shoe machines



Dec. 6, 1960 D. c. PlLZ 2,962,737

WORK SUPPORTS FOR SHOE MACHINES Filed Dec. 9, 1958 2 Sheets-Sheet 1[nvezv tor Dona/d (cil Pilz.

By his Attorney 1950 D. c. PlLZ 2,962,737

WORK SUPPORTS FOR SHOE MACHINES Filed Dec. 9, 1958 2 Sheets-Sheet 22,962,737 WORK SUPPORTS FQR SHOE MACHINES Donald Cecil Pilz, Leicester,England, assignor to United Shoe Machinery Corporation, Flemington,N.J., a corporation of New Jersey Filed Dec. 9, 1958, fler. No. 779,236Claims priority, application Great Britain Feb. 7, 1958 9 Claims. (Cl.12-86.7)

This invention relates to shoemaking machines and more particularly tomachines in which operations are performed on shoe parts and/or shoes invarious stages of manufacture which are mounted on and firmly clamped toa last. The invention is particularly directed to a machine for clampinga last with a shoe part or parts firmly attached thereto in a jack forpresentation to an operating tool.

One of the first operations in the fabrication of shoes which requiresashoe part to be clamped to a last is the shaping of an insole to thecontours of the last. The insole is generally cut from flat stock andusually in a horizontal plane with the result that when the insole istacked to the bottom of a last it sometimes does not precisely registerwith the last which has many curvatures on and about its bottom surface.To insure, therefore, a correct size insole for a particular last, it isa common practice initially to cut the insole somewhat longer at itsheel end than the dimension of the last for which it is intended andwhen the insole has been tacked to the last, it is then trimmed toregister precisely with the periphery of the last bottom. It isdesirable that the finished shoe have .a smooth continuous curve fromthe upper edge of the shoe at the heel end to its heel seat portion. Forthis reason it is frequently desirable to bevel the edge of the insoleat an angle such that the curve represented by the back of the last andthe contour of the periphery of the insole are substantially continuous.When the insole is made of leather it is a relatively simple operationto trim and bevel its edge by the use of a rotary cutter. However, inrecent years it has become a practice in shoe manufacturing to reinforceinso es with hard fibrous substances. resulting in a more difficult taskfor an operator and for the cutting tools of machines previously used totrim and bevel leather insoles. Furthermore, difliculty also arises fromthe fact that the resist ance offered by the hard fibrous substance tothe action of the trimming tool or cutter tends to displace the inso erelatively to the last bottom in spite of tacks which are inserted toprevent such relative movement. Clamping means for securing the insolesto the last bottom have hitherto been available for this operation buthave not been of a nature to hold the insole firmly against suchdisplacement, nor have such clamps been convenient to operateparticularly when a large range of sizes of shoes are being made. Innumerous other shoe manufacturing operations it is necessary to clampshoe parts or partially fabricated shoes firmly on their last to assureaccurate presentation to operating tools.

Accordingly, it is an object of this invention to provide a machine foroperating on a shoe part mounted on a last, the machine havingconvenient clamping means exerting sufficient force to hold the part inengagement with the last against displacement relatively thereto as themachine operates on the shoe part.

A second object of this invention is to provide a shoe machine havingclamping mechanism which is simple to operate and which does not requirestrenuous eflort on the part of the operator to effect such clamping.

Another object of this invention is to provide a shoe machine havingclamping mechanism which is hydraulically operated and whichautomatically compensates for fluid pressure variations in order toeffect a constant clamping pressure.

Another object of the invention is to provide a machine for trimmingreinforced insoles, the machine having convenient work clamping means ofsuflicient strength to hold the insole against displacement relativelyto the last bottom with constant pressure as the trimming cutter acts onthe reinforcing material.

In a copending application Serial No. 630,940, filed December 27, 1956,in the name of B. I. M. Murphy (now US. Patent No. 2,892,199, grantedJune 30, 1959), there is disclosed a machine for clamping shoe partsagainst a last positioned in a jack for presentation to an operatingtool. In many respects the present invention is similar to the Murphymachine but it is considered to be an improvement thereover. The Murphymachine is an insole trimmer having a cutter and an operator actuatedjack mounting a hydraulically operated clamping mechanism comprising afirst clamp and a second clamp movablelrelatively thereto by pressurizedfluid. By this clamping mechanism a last with an attached insole may befirmly gripped between the clamps while being-presented to the cutter.Hydraulic operating fluid is supplied to the clamping means from atreadle operated fluid pump comprising piston-cyl-inder mechanism. Inorder to compensate for variations in pressure of the operating fluidthe piston-cylinder mechanism is provided with adjustable means topermit movement of the cylinder relatively to the piston to vary thevolume within which the operating fluid is compressed. I

In accordance with the various features of the present invention,although the same clamping means are provided, the treadle operatedpiston and cylinder mechanism is eliminated and is replaced by a moreaccurate fluid pressure regulating mechanism including a fluid pump fordirecting pressurized operating fluid to the clamps and a valve forautomatically controlling the pressure of the operating fluid. Amanually operated lever is conveniently mounted on the jack within thegrasp of the operator while he is moving the jack to present the work tothe tool. Through appropriate linking means the lever actuates thecontrol valve which is located remotely from the jack. The valve whichis associated with the fluid pump includes extremely sensitive pressurerelief valve means to compensate for variations in pressure of theoperating fluid thereby to maintain the pressure at the clamping meansautomatically at a substantially constant value.

The above and other features of the invention including various noveldetails of construction and combinations of parts will now be moreparticularly described with reference to the accompanying drawings andpointed out in the claims.

In the drawings,

Fig. 1 is a front elevation partly broken away with portions shown insection of an insole trimmings ma chine embodying the invention;

Fig. 2 is a detail view on an enlarged scale partly in section of anoperative portion of the machine shown in Fig. l with the parts in workclamping positions; and

Fig. 3 is a detail view similar to Fig. 2 with the parts in normal orinoperative positions.

The apparatus illustrated in the drawings is an insole trimming machinesimilar to that disclosed in the abovementioned Murphy patent andadapted to trim and bevel the peripheral portions of an insole securedto a last, the insole and last being firmly clamped together during thetrimming operation. It will be understood that this illustrative machineis selected for description of the invention and is. not to be construedas a limitation thereof. The shoe part need not necessarily be an insolenor the tool a trimming cutter. Referring to Fig. 1, which shows thefront of the machine as viewed by an operator presenting a shoe thereto,the machine comprises a base 2 with a frame 4 mounted thereon in whichis journaled a horizontally extending shaft 6 that carries a tool in theform of a trimming and beveling cutter 8. Connected to the frame 4 is aC1-shaped work supported jack 16 of the type illustrated in the Murphypatent and which forms no part of the present invention. The jack 10carries clamping means comprising a first rota-table clamp 12 and asecond rotatable clamp 14 movable bodily relatively thereto in axialalignment therewith.

The second clamp 14 is formed on the end of a spindle constituting apiston movable within a horizontal cylinder 15 considered part of theclamping member and mounted on the jack 1% Connected to the cylinder isthe upper portion of a flexible pipe or fluid conduit 16. The cylinder15 forms that portion of the jack which is normally grasped by theoperator to assist in guiding the edge of the work piece clamped to alast in the jack to the trimming and beveling cutter 8. Normally, thecylinder 15 would be grasped by the operators left hand while the lastwith the work attached is rotated by the right hand of the operator inthe jack relatively to the cutter.

Manually operated control means in the form of a lever 17 is mounted onthe cylinder 15, hereinafter known as the clamping cylinder, in positionto be readily grasped by the operator as his hand encircles it. Thelever 17 which is pivoted on the clamping cylinder is connected to thecore of a sheathed Bowden cable 18, which, along with the fluid conduit16, passes downwardly of the machine. The cable and conduit are bothconnected in manner hereinafter to be described, to a fluid controlvalve 20 mounted in a hydraulic fluid reservoir 21 located within thebase 2 of the machine. Also located within the reservoir 21 andconnected to the valve 20 is a fluid pump 24.

The fluid control valve 20 comprises a main valve block 26 secured tothe side of the reservoir 21 and provided with an inlet passageway 28which communicates with the pump 24 by way of a fitting 30 and a pipe32. Thevalve 20 also communicates by way of a passage 34 and fitting 36with the fluid conduit 16 leading to the clamping cylinder 15. Anotherpassageway 38 in' the valve block 26 communicates directly with theinterior "of the reservoir 21. The level of fluid within the reservoiris maintained at a sufficient height H whereby the valve 20 iscompletely submerged at all times. Still another passageway 40 in theblock 26 communicates with a relief valve 42.

A sleeve 44 is fitted in the interior of the block 26 and together withthe block forms the body of the valve 20 also known as the valvecylinder. A constant diameter bore 45 is formed in the interior of thesleeve 44 and a series of co-planar radially spaced passageways 33, 35and 37 each leading to an annular recess, place the bore incommunication with the passageways 28, 38 and 40, respectively.

Slidable in the bore 45 is a spool valve member 46, the upper end ofwhich is secured by a coupling 48 to the core of the Bowden cable 18. Tovary the effect on the control valve 20 of movement of the lever 17, thesheathing or outer casing of the Bowden cable is provided with aconventional adjusting means in the form of a threaded adjustablecoupling 49. Rotation of the coupling varies the effective length of thecable whereby the operative position (Fig. 2) of the spool ,ralvefl 46may be adjusted relatively to the bore 45. A

return spring 50 is compressed between the adjustable coupling 49 andthe coupling 48.

Enlarged heads 51, 53 on the spool valve 46 are formed to have asliding, fluid tight fit within the bore 45. Separating the enlargedportions 51 and 53 and slidably mounting a sleeve member or floatingpiston 52 is. a central spindle 54 of lesser diameter than the portions51 and 53. The floating piston 52, which is of the same diameter as theenlarged portions 51 and 53, normally floats between two springs 56 and57 of similar strength positioned one on either side of the member 52and compressed against the enlarged portions 51 and 53. These springsnormally maintain the sleeve member 52 midway along the spindle 54between the enlarged portions 51 and 53, as seen in Fig. 3. Longitudinalgrooves or bleed passageways 58 formed in the floating piston 52 providecommunication between two main valve spaces 60 and 62, definedrespectively as the'space between the floating piston 52 and theenlarged portion 51 and the space between the floating piston 52 and theenlarged portion 53. a V

The relief valve 42 is mounted on the valve block 26 in communicationwith the passageway 40 and is a sensitive, nevertheless, conventionaltype comprising a valve body 64 in which there is disposed a movableneedle valve plunger 66 having a conical face 67 urged by a spring 68toward a valve seat 69 formed on the valve body 64. The compression ofthe spring 68, and hence the opening pressure of the relief valve 42, ispreset by an adjusting screw 70 threaded in the valve body 64 andmaintained in adjusted position by a lock nut 72. The interior of therelief valve 42 communicateswith the reservoir 21 through relief ports74.

The mechanism operates in the following manner. In its normal orinoperative position, the spool valve member 46 occupies the positionshown in Fig. 3, whereby the floating piston 52 floats betweenthesprings 56, 57 midway along the spindle 54. The passageways 33 areunblocked whereby the conduit 16 isin communication with the pump 24.The passageways 35 are likewise unblocked so that the space 60 is incommunication with the interior of the reservoir 21. Thus, fluiddisplaced by the pump 24 from the reservoir circulates through the pipe32, the valve space 60 and back to the reservoir without producing anappreciable pressure rise in the space 60. Consequently, the fluidpressure in the clamping cylinder 15 which communicates with the Space60 does not rise sufficiently to move the .clamp 14 into clampingposition. A return spring in the clamping cylinder 15 (not shown)displaces the clamp 14 away from clamping position.

When it is desired to produce a clamping effect at the jack 10 by movingthe clamp 14 toward the clamp 12, the hand lever 17 is displaced towardthe cylinder 15, which, through the Bowden cable 18, displaces the spoolvalve member 46 upwardly from the Fig. 3 or inoperative position. Whenthe valve 46 is initially moved, the slidable floating piston 52 israised along with it and continues to occupy a central position on thespindle 54 such that the passageways 35 are completely blocked. In thisposition the space 60 does not communicate with the reservoir 21 and thepressure rises in the space 60 and hence within the clamping cylinder 15with which it communicates. When the pressure in the cylinder 15 hasrisen sufficiently to overcome the force of the return spring in thecylinder, the clamp 14 is displaced and is maintained in clampingposition until the hand lever 17 is released whereupon the spring 50returns the valve member 46 to its normal inoperative position as justdescribed with reference to Fig. 3.

Again with reference to Fig. 2, as the pressure increases in the space60, so does the pressure in the space 62 below the floating piston 52.This is because the spaces are in communication by way of the groovesbleed p ays .5 When this pressure reaches that at which the relief valve42 is set to operate. the movable needle valve plunger .66 is displacedand the pressure within the space 61? is relieved due to the flowthrough the passageways 37, 40, and 74. This fluid is replaced by fluidflowing through the grooves or bleed passageways 58 from the space 60,equilibrium flow conditions being reached when the pressure in the space62 has diminished to a value just above that required to maintain therelief valve 42 in open condition. Should the pressure in the space 62drop below this value for any reason, the relief valve 42 will closepermitting the pressure again to build up until it is suflicient to openthe valve.

As will be seen, a greater area of the conical face 67 of the needlevalve plunger 66 is subjected to fluid pressure in the passageway 40,and hence in the space 62, when the valve is opened rather than when itis seated in the seat 69. Consequently, when the valve is open, asmaller pressure in the space 62 can overcome the, com pressive force ofthe spring 68 than when the valve is closed. Hence, the closing pressureis less than the opening pressure.

The drop in pressure in the space 62 resulting from the opening of therelief valve 42 produces a differential pressure across the sleevemember 52 which, as a result, is displaced downwardly of the spindle 54and the sleeve 44, additionally compressing the spring 57 and permittingthe spring 56 to expand somewhat. This continues until the forces of thecombined spring and fluid pressure acting downwardly upon the sleevemember 52 are in equilibrium with those acting upwardly.

The valve 20 is so designed and adjusted by means of the screwadjustment 70 that when equilibrium conditions have been attained, thefloating piston 52 will float with its upper edge partially unblockingthe passageways 35. In this condition there is relief flow from thespace 69 which prevents the pressure in that space and hence in theclamping cylinder from rising above the desired maximum value. In otherwords, the pressure in the clamping cylinder 15 is controlled by thevolume of the space 60 which communicates with it.

The bleed or flow through the grooves 58 is merely sufficient tomaintain the relief valve 42 slightly open, handling a small flow and ina very sensitive condition. In this sensitive condition the relief valve42 is able to exercise a very stable control, over the equilibriumpressure in the space 60 and in the clamping cylinder 15 by controllingthe diflerential fluid pressure across the sleeve member 52. Thisresults in a substantially constant clamping pressure on the work.Furthermore, any pressure disturbances in the system are rapidly andautomatically corrected and a constant clamping Pressure is maintained.

As mentioned above, when the operator releases the lever 17 at the endof the trimming operation the respective parts of the valve 20 arereturned to their normal or Fig. 3 positions and the pressure within theclamping cylinder 15 is relieved permitting the work to be removed fromthe jack.

It will be appreciated that the above-described fluid pressure means arerelatively simple in nature and effect not only the operable movement ofthe work clamping member 14 but also include extremely sensitivepressure control means for insuring that the clamping pressure will bemaintained at a substantially constant but not excessive value.Furthermore, the control member for operating the entire system is soconvenient y positioned on the machine that the operator is not requiredto remove a hand from the work or jack to actuate the member, nor isfoot treadle operation required.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. In a machine for operating on a shoe part on a last, a tool, amanually operated jack movable toward and. away from the tool, fluidoperated means for clamping in the jack a last with part of a shoeattached thereto, a fluid pump for directing pressurized operating fluidto the clamping means, valve means for controlling the pressure of theoperating fluid, and manually operated control means mounted on the jackfor operating said valve and positioned to be grasped by an operatorwhile operating said jack, said fluid pump and said valve means beinglocated remotely from said jack.

2. In a machine for operating on a shoe part mounted on a last, a tool,a jack for supporting part of a shoe and last for presentation to thetool, fluid operated means for clamping the shoe part and last in thejack, a fluid pump, a valve for controlling the pressure of operatingfluid supplied to the clamping means by said pump, and manually operatedcontrol means comprising a lever movably mounted on the jack andoperatively connected to the control valve, said fluid pump and controlvalve. being located remo ely of sai j ck- 3. In a machine for operatingon a shoe part mounted on a last, a tool, a jack for supporting part .ofa shoe and last for presentation to the tool, fluid operated means forclamping the shoe part and last in the jack, a fluid pump, a valve forcontrolling the pressure of operating fluid supplied to the clampingmeans by said pump, manually operated control means comprising a levermovably mounted on the jack and operatively connected to the controlvalve, said fluid pump and control valve being located remotely of saidjack, and adjusting means operatively connected to the control valve tovary the eflect on said control valve of movement of said lever.

4. In a machine for operating on a shoe part mounted on a last, a tool,a jack for supporting part of a shoe and last for presentation to thetool, fluid operated means for clamping the shoe part and last in thejack, a fluid pump, a valve for controlling the pressure of operatingfluid suppl to the clamping means by said pump comprising a valvecylinder, a piston dividing said cylinder into upper and lower chambers,the fluid pump and the clamping means being at all times incommunication with the upper chamber, a fluid relief passagewaycommunicating with the interior of the cylinder, and manually operatedcontrol means for shifting the piston from a first position wherein therelief passageway is unblocked and in communication with the upperchamber to a second position wherein the relief passageway is blocked bythe piston whereby the pressure in the upper chamber and at saidclamping means rises in order to effect a. clamping move ment.

5. In a machine for operating on a shoe part mounted on a last, a tool,a jack for supporting part of a shoe and last for presentation to thetool, fluid operated means for clamping the shoe part and last in thejack, a fluid pump, a valve for controlling the pressure of operatingfluid supplied to the clamping means by said pump comprising a valvecylinder, a piston dividing said cylinder into upper and lower chambers,a passageway through said piston placing said upper and lower chambersin communication, both the fluid pump and the clamping means being atall times in communication with the upper chamber, a fluid reliefpassageway communicating with the interior of the cylinder, anadjustable relief valve in communication with the lower chamber forregulating the pressure therein and consequently in said upper chamberand at the clamping means, and means for shifting said piston from afirst position wherein the relief passageway is unblocked and incommunication with the upper chamber to a second position wherein therelief passageway is blocked by the piston whereby the pressure in theupper chamber and the clamp ing means rises in order to effect aclamping movement.

6. In a machine for operating on a shoe part mounted on a last, a tool,a jack for supporting part of a shoe and last for presentation to thetool, fluid operated means for clamping the shoe part and last in thejack, a fluid pump, a valve for controlling the pressure of operatingfluid supplied to the clamping means by said pur'npcom- .prising a valvecylinder a piston, dividing said cylinder into upper and lower chambers,a passageway through 'said piston placing said upper and lower chambersin communication, both the fluid pump and the clamping means being atall times in communication with the upper chamber, a fluid reliefpassageway communicating with the interior of the cylinder, anadjustable relief valve in communication with the lower chamber forregulating the pressure therein and consequently in said upper chamberand at the clamping means, means for shifting said piston from a firstposition wherein the relief passageway is unblocked and in communicationwith the upper chamber to a second position wherein the reliefpassageway is blocked by the piston whereby the pressure in the upperchamber and the clamping means rises in order to effect a clampingmovement, said fluid pump and control valve being. located remotely ofsaid jack and said manually operated control means being a lever movablymounted .on the jack andoperatively connected to the control valve, andadjusting means operatively connected to the :control valve to vary theefiect on said control valve of movement of said lever.

7. In a machine for operating on a shoe part mounted on a last, a tool,a jack for supporting part of a shoe and last for presentation to thetool, fluid operated means for clamping the shoe part and last in thejack, a fluid pump, a valve for controlling the pressure of operatingfluid supplied to the clamping means by said pump comprising a valvecylinder, a floating piston dividing said cylinder into upper and lowerchambers, a passageway through said floating piston placing said upperand lower chambers in communication, both the fluid pump and the'clamping means being at all times in communication with the upperchamber, a fluid relief passageway communicating with the interior ofthe cylinder, means for shifting :said floating piston from a firstposition wherein the relief passageway is unblocked and in communicationwith the upper chamber to a second position wherein the reliefpassageway is blocked by the piston whereby the pressure in the upperchamber and the clamping means rises in order to effect a clampingmovement, an adjustable relief valve in communication with the lowerchamber set to open when the pressure therein reaches a predetermined'value, whereupon fluid is relieved from said lower chamber causing thepressure in the upper chamber to displace means,

, 8. In a machine for operating on a shoe part mounted on a last, atool, a jack for supporting part of a shoe and last for presentation tothe tool, fluid operated means for clamping the shoe part and last inthe jack, a fluid pump, a valve for controlling the pressure ofoperating 8 fluidsupplied to the clamping means by said pump comprisinga spool valve member slidable in the cylinder and having upper and lowerpiston heads joined by a spindle, a floating piston on said spindledividing said cylinder into upper and lower chambers, springs of equalstrength in the valve cylinder compressed between said floating pistonand said piston heads, the fluid pump and the clamping means being atall times in communication with the upper chamber, a fluid reliefpassageway communicating with the interior of said valve cylinder, meansfor shifting the spool valve member from a first position wherein the relief passageway is unblocked and in communication with the upper chamberto a second position wherein said relief passageway is blocked by thefloating piston whereby the pressure in the upper chamber and at theclamping means rises in order to effect a clamping movement. 9. In amachine for operating on a shoe part mounted on a last, a tool, a jackfor supporting part of a shoe and last for presentation to the tool,fluid operated means for clamping the shoe part and last in the jack, afluid pump, a .valve for controlling the pressure of operating fluidsupplied to the clamping means by said pump comprising a spool valvemember slidable in the cylinder having upper and lower piston headsjoined by a spindle, a floating cylinder, means for shifting the spoolvalve member from a first position wherein the relief passageway isunblocked and in communication with the upper chamber to a secondposition wherein said relief passageway is blocked by the floatingpiston whereby the pressure in the upper chamber and at the clampingmeans rises in order to eflect a clamping movement, an adjustable reliefvalve in communication with the lower chamber set to open when thepressure therein reaches a predetermined value,

whereupon fluid is relieved from said lower chamber causing the pressurein the upper chamber to displace the floating piston toward said firstposition to eflect unblocking of said relief passageway to reducefurther the pressure in the upper chamber and at the clamping means.

References Cited in the file of this patent UNITED STATES PATENTS2,359,395 Stacey Oct. 3, 1944 2,388,820 Bonnell Nov. 13, 1945 2,541,132Thresh Feb. 13, 1951 2,580,128 Renick Dec. 25, 1951 2,636,509 Cizek Apr,28, 1953 2,639,102 Ball May 19, 1953

